3-DIMENSIONAL DISTRIBUTION OF LIMONIN, LIMONOATE A-RING MONOLACTONE, AND NARINGIN IN THE FRUIT TISSUES OF 3 VARIETIES OF CITRUS-PARADISI

Limonin and naringin are the two major bitter compounds in Citrus para disi (grapefruit), and tissue-specific patterns of their distribution are well-established. This study was undertaken to determine the distr ibution of these compounds within Duncan, Marsh, and Thompson Pink tis sues using three-dimensional fruit dissection (600-900 samples per fru it) and highly specific radioimmunoassays for limonin and naringin qua ntification. Results from a GLM ANOVA showed that there was no radial distribution pattern of limonin or naringin accumulation in these frui t. There were statistically significant differences in the axial distr ibution of these compounds within the fruit tissues. The limonin conce ntration in flavedo, albedo, outer segment membrane, and juice vesicle s increased toward the distal end of the fruit. Naringin concentration s in flavedo, albedo, and outer segment membranes tended to be higher in the center portion of the fruit. Limonoate A-ring monolactone level s are also reported.